The present invention disclosed herein relates to methods for fabricating Field Effect Transistors (FETs), and more particularly, to methods for fabricating compound semiconductor FETs.
Compound semiconductor FETs are widely used in application devices of microwave or millimeterwave (10 GHz˜100 GHz) bands because they have better speed characteristics than silicon-based semiconductor devices. An FET reduces the electric field of a gate electrode and a drain electrode to achieve a high breakdown voltage. The FET may include a field plate that reduces the capacitance between the gate electrode and the drain electrode. The field plate may be formed on a dielectric layer between the gate electrode and the drain electrode.
However, the typical gate electrode is formed before the field plate. Therefore, the gate electrode and the field plate require a plurality of metal layer forming processes and a plurality of lithography processes, thus degrading the productivity.